JP3873328B2 - Grooving method and processing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a processing method and a processing apparatus for performing grooving processing such as a V-groove on a work such as a silicon wafer used for an optical fiber array or the like.
Specifically, the method and apparatus of the present invention is an ultra-precision machining that realizes high-precision machining by combining a measuring machine that measures the height of the upper surface of the workpiece that operates in the vertical direction in grinding using a grindstone blade. It makes technology possible.
[0002]
[Prior art]
When many grooving processes are performed on the entire area of the workpiece, the height of the upper surface of the workpiece is increased due to factors such as the shape error of the chuck upper surface, unevenness of the workpiece thickness over the entire workpiece area, and foreign matter adhesion when the workpiece is set on the chuck. Strictly it will not be horizontal.
Therefore, even if grooving is performed with the spindle height to which the grindstone blade is attached being constant, the groove depth from the work upper surface of the processed groove is not constant throughout the work.
[0003]
Furthermore, when a large number of parts are produced by making the workpiece into chips, parts with different machining groove depths depending on the partial height variation of the workpiece are produced, which is a factor that reduces the yield rate. It was.
[0004]
[Problems to be solved by the invention]
In the work grooving method in which the height of the spindle is constant as in the prior art described above, the shape accuracy of the chuck for setting the work and the uniformity of the work thickness over the entire work must be strictly controlled.
However, it is not only difficult to manage them, but when considering the non-defective rate of workpiece thickness and the grooving work on the workpiece, and considering the non-defective rate of chips, the productivity is poor and the non-defective rate decreases. There was a problem to do.
[0005]
In addition, when a workpiece is set on a chuck whose upper surface is substantially horizontal and the spindle is moved in both the upper and lower directions (Z-axis direction) during processing so as to follow the height fluctuation of the upper surface of the workpiece, Positioning accuracy is poor due to backlash in the vertical movement of the spindle in the Z-axis direction on the slide surface and changes in the attitude of the spindle. There was a problem to do.
[0006]
[Means for Solving the Problems]
As a result of various studies on the above problems, the present inventor can perform grooving with high accuracy by combining a grinding machine using a grindstone blade with a measuring machine for measuring the height of the upper surface of the workpiece. It has been found that the yield rate of the workpiece parts can be increased, and the present invention has been completed.
That is, the present invention provides:
(1) In a grinding method for grooving a workpiece such as a silicon wafer by rotating a grindstone blade at high speed,
(B) With the workpiece set on the upper surface of the chuck tilted with respect to the horizontal plane, (b) Based on the result of measuring the height of the workpiece upper surface with a measuring machine in advance , the workpiece upper surface height varies partially the processed substantially constant depth of machining grooves in from the work top in the work entire area by correcting the vertical operation of the spindle during grooving, always vertically downward or to the inclined direction of the (c) Further work upward moving grindstone blade feed direction in only one direction, to provide a grooving process of the work. Also,
[0007]
(2) It is also characterized in that the angle of inclination of the chuck with respect to the horizontal plane is 30 ° or less. Also,
(3) The measuring machine that measures the height of the upper surface of the workpiece is also detachable from the processing machine. Also,
(4) a measuring instrument for measuring the height of the workpiece upper surface in a state that workpiece is set on the inclined chuck with respect to the horizontal plane, based on the measurement result by the measuring instrument, partial of the work top height The fluctuation is reflected and corrected in the vertical movement of the spindle during grooving, and the grindstone blade always moves in the feed direction that is either vertically downward or upward with respect to the tilt direction of the workpiece. Provided is a workpiece grooving apparatus in which a grinding machine composed of a grindstone blade for grooving at a depth and width is detachably combined.
[0008]
Hereinafter, the present invention will be described in detail with reference to the drawings.
[Action]
(I ) In the present invention, a large number of parts can be obtained from a workpiece at a high yield rate without strictly managing the shape accuracy of a chuck for setting a workpiece such as a silicon wafer and the uniformity of the workpiece thickness over the entire workpiece. To produce
(B) With the workpiece set on the upper surface of the chuck tilted with respect to the horizontal plane, (b) Based on the result of measuring the height of the workpiece upper surface with a measuring machine in advance , the workpiece upper surface height varies partially the processed substantially constant depth of machining grooves in from the work top in the work entire area by correcting the vertical operation of the spindle during grooving, always vertically downward or to the inclined direction of the (c) Further work By moving the grindstone blade in the feed direction in only one direction upward ,
The depth of the machining groove from the workpiece upper surface can be machined almost constant over the entire workpiece (claim 1).
[0009]
Conventionally, when this correction operation is performed in both the upper and lower directions, the error increases. However, if the chuck surface is given a certain inclination as in the present invention, even if there is waviness on the workpiece surface, the spindle movement is well corrected in one direction. It is enough.
In this way, by tilting the upper surface of the chuck for setting the workpiece with respect to the horizontal plane, the Z-axis is always vertically downward without moving the spindle in both the upper and lower directions of the Z-axis so as to follow the height fluctuation of the upper surface of the workpiece. Alternatively, the spindle can follow the fluctuation in the height of the workpiece upper surface with high accuracy only by upward movement.
In this case, an error occurs in the movement when the direction of the normal movement is changed, but there is an advantage that the movement can be performed with high accuracy when the movement is in one direction as in the present invention.
[0010]
(Ii ) Further, by setting the inclination angle of the upper surface of the chuck on which the workpiece is set to the horizontal plane to 30 ° or less, preferably 10 ° or less, more preferably 5 ° to 8 °, the movement direction (X The amount of deviation from the target value of the depth of the machining groove when the positioning in the axial direction is deviated from the command position can be reduced (claim 2).
[0011]
(Iii) In addition, the measuring machine for measuring the height of the workpiece upper surface is detachable from the processing machine, so that the measuring machine can be ground by removing the measuring machine from the processing machine during processing. Since it is not exposed to liquid, grinding scraps, etc., it is possible to prevent deterioration of measurement accuracy and deterioration of the measuring machine itself (claim 3).
(Iv) the processing apparatus of the present invention, in a state of setting the work on a chuck tilted with respect to the (b) horizontal, and a measuring instrument for measuring the height of the workpiece upper surface, (b) measurement of the measuring instrument Based on the result, the partial fluctuation of the workpiece upper surface height is reflected / corrected in the vertical movement of the spindle during grooving, and (c) is always vertically downward or upward relative to the workpiece tilt direction. is moving grindstone blade feed direction direction only, and the grinding machine comprising a grinding wheel blade grooving at a constant depth and width to the work top by rotating high velocity, are combined detachably (d) (Claim 4).
[0012]
【Example】
The present invention is specifically described by the following examples, but the scope of the present invention is not limited by the description.
1 and 2 are schematic views for explaining an embodiment of a grooving method and its processing apparatus according to the present invention. FIG. 1 shows a state when measuring the surface height of the workpiece. FIG. 2 shows a state during grooving.
[0013]
1 and 2, 1 is a chuck, 2 is a workpiece, 3 is a workpiece upper surface height measuring device, 4 is an inclination angle, 5 is a stage, and 6 is a grindstone blade.
As shown in FIGS. 1 and 2, with a chuck 1 having an upper surface inclined at 8 ° with respect to a horizontal plane, with a 4-inch silicon wafer (work) 2 having a thickness of 1 mm set, a contact type shape measuring machine (Keyence Corporation) The height fluctuation of the workpiece upper surface was measured with a long range contact displacement meter 3).
[0014]
The data sampling interval when measuring the height of the workpiece upper surface over the entire workpiece was 5 mm in both the stage motion direction (X axis) and the machining groove pitch direction (Y axis). After the measurement, the contact-type shape measuring machine 3 is removed from the grooving machine 8, and the data of the workpiece upper surface height direction (Z axis) at each (X, Y) coordinate value is moved up and down during the machining. By providing feedback, high-precision grooving with a variation in the depth of the machining groove from the workpiece top surface of ± 0.3 μm over the entire workpiece was realized.
Further, the wafer work 2 was further chipped to produce a large number of parts. As a result, a good value of 90% or more was obtained.
[0015]
【The invention's effect】
As described above, in the present invention, in a state that workpiece is set on the upper surface of the chuck inclined to the horizontal plane, and measuring the height of the workpiece upper surface in advance by the measurement machine, the height portion of the workpiece upper surface By reflecting and correcting the dynamic fluctuations in the vertical movement of the spindle during grooving, the machining groove depth from the workpiece upper surface can be machined uniformly throughout the workpiece. A large number of parts can be produced from a workpiece at a high yield rate without strictly controlling the accuracy or uniformity of the thickness of the workpiece over the entire workpiece.
[Brief description of the drawings]
FIG. 1 is a schematic diagram for explaining an embodiment of a grooving method and a processing apparatus thereof according to the present invention, and shows a state at the time of measuring the surface height of a workpiece.
FIG. 2 is a schematic diagram for explaining an embodiment of a grooving method and a processing apparatus according to the present invention, and FIG. 2 shows a state during grooving.
[Explanation of symbols]
1 Chuck 2 Workpiece 3 Workpiece Top Height Measuring Machine 4 Inclination Angle 5 Stage 6 Whetstone Blade

Claims (4)

In a grinding method for grooving a workpiece such as a silicon wafer by rotating the grinding wheel blade at high speed,
With the workpiece set on the top surface of the chuck that is tilted with respect to the horizontal plane, the spindle is used to measure partial fluctuations in the workpiece top surface height during grooving based on the result of measuring the height of the workpiece top surface with a measuring machine in advance. By correcting the vertical movement of the workpiece, the depth of the machining groove from the upper surface of the workpiece is processed to be almost constant over the entire workpiece , and the feed direction is always in the downward or upward direction with respect to the tilt direction of the workpiece. A method for grooving a workpiece, characterized by moving a grindstone blade . 2. The workpiece grooving method according to claim 1, wherein an inclination angle of the chuck with respect to a horizontal plane is 30 [deg.] Or less. 2. The grooving method for a workpiece according to claim 1, wherein the measuring machine for measuring the height of the upper surface of the workpiece is detachable from the processing machine. A measuring instrument for measuring the height of the workpiece upper surface in a state of setting the work on a chuck which is inclined relative to the horizontal plane, based on the measurement result by the measuring instrument, the groove partial variations of the work top height Reflected and corrected in the vertical movement of the spindle during machining, and the grindstone blade always moves in a feed direction that is only vertically downward or upward with respect to the tilt direction of the workpiece. and in which it characterized in that a grinding machine comprising a grinding wheel blade grooving is combined detachably, grooving device of a work.

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